Yes, Those Are American Elms
By Mark Zoeller
Guests who enter the front plaza at the Louisville Zoo are greeted by a pleasant surprise, a comfortable plaza area with guest services facilities (complete with family style restrooms and a first aid office) and pleasant landscaping. To expand the plaza, much of the old landscaping had to be removed and was transplanted to Gorilla Forest.
The front plaza landscape is intended to be representative of our Kentucky flora. The plantings and the huge limestone boulders that create planters throughout the entry help us achieve that look.
The project provided the opportunity to create much more of a plaza feel with unimpeded traffic flow and open site lines. To provide shade for this gathering area, tree cut outs were allowed in the concrete.
Much discussion ensued regarding the species of tree that would best represent our Kentucky landscape and stand up to the urban requirements that would be needed.
Working with John Korfhage, of Korfhage Landscape and Designs, the Zoo was able to come up with the perfect species for the area, the American elm. After nearly a fifty year absence, the American elm is back and available for planting.
These "new" elms are the result of a breakthrough in research that identified types of American elms that can survive Dutch elm's disease. Dutch elm's disease is a fungus that arrived in America in 1930 and devastated a species of tree that once dominated area landscapes. Parks, parkways and campus plantings were decimated as the disease spread.
For obvious reasons, the American elm fell out of favor and had not been available commercially since the 1940's.
The rebirth of the American elm is due to research at the National Arboretum through the Department of Agriculture. Denny Townsend, a tree geneticist, discovered three variables of American elm that can tolerate Dutch elm disease.
The trees located on the Zoo's front plaza are Princeton elms. The name comes from the town of Princeton, N.J. where the elm still lines the streets. It is unclear what gives these trees a genetic ability to tolerate Dutch elm's disease.